A polarizing plate is applied to various image display devices such as a liquid crystal display and an organic light emitting device. The polarizing plate mainly used in recent years is used in a form where a protection film is laminated on one surface or both surfaces of a PVA polarizer oriented and manufactured by a method of dyeing iodine and/or dichromatic dyes on a polyvinyl alcohol (hereinafter, PVA)-based film, cross-linking the iodine and/or dichromatic dyes by using a boric acid and the like, and then stretching.
Meanwhile, there is a current trend toward increasing sliminess of the image display device, and in order to implement a large screen, the image display device has been developed toward a trend where thicknesses of a bezel portion and an edge where the screen is not displayed are minimized. Further, in order to implement various functions, parts such as cameras tend to be equipped in a display device, and in consideration of a design factor, efforts of providing various colors to a product logo or edge region or decoloring the product logo or edge region have been made.
However, in the case of an existing polarizing plate, since an entire region of the polarizing plate is dyed with the iodine and/or dichromatic dyes, the polarizing plate has a dark black color, and as a result, there are problems in that it is difficult to provide various colors to the image display device, and particularly, in the case where the polarizing plate is positioned on the parts such as the cameras, 50% or more of the intensity of radiation is absorbed by the polarizing plate to reduce visibility of a camera lens.
In order to solve the problems, a method of physically removing a portion of the polarizing plate, which covers the camera lens, by piercing a hole (boring) in the portion of the polarizing plate by a methods such as punching and cutting has been commercialized.
However, the aforementioned physical method degrades an appearance of the image display device, and the polarizing plate may be damaged and a step may be formed at a boundary portion due to characteristics of a process of piercing the hole. Meanwhile, in order to prevent damage such as tearing of the polarizing plate, a bored portion of the polarizing plate should be formed in a region that is sufficiently far away from a corner, and as a result, there is a problem in that in the case when the polarizing plate is applied, the bezel portion of the image display device is relatively widened to deviate from a current narrow bezel design trend of the image display device. Further, there is a problem in that as described above, in the case where a camera module is equipped in the bored portion of the polarizing plate, since the camera lens is exposed to the outside, contamination and damage of the camera lens easily occur when the camera lens is used over a long period of time.
Accordingly, there is a demand for developing a novel process for local depolarization or polarization removal of the polarizing plate corresponding to an appropriate size to overcome the aforementioned problems and to be suitable for installation of the parts such as the camera module in the image display device.